About Our Cut Tulip Trials

The yearly cut tulip trials in the Flower Bulb Research Program are designed to gain experience with "newer" cultivars under North American (Northeast USA) forcing conditions. We receive bulbs (usually 12/+ cm) in mid September, and start cooling batches of them about Oct 1. Through a combination of cooling start dates and forcing dates, a range of cold-weeks spanning approximately 14 to 22 weeks is obtained. The basic cooling strategy is to start at 9C, then reduce temperature after planting, to an ultimate low of about 1C.

Fifteen bulbs are planted into a 10" bulb pan, giving a density similar to normal commercial planting. We use a peat-lite mix, most recently this has been Lambert LM-111. Plants are fertilized twice a week with calcium nitrate (2 lb/100 gal) as a preventative for stem topple. Bulbs are forced at 63F (17C) night temperature. Days are usually several degrees warmer.

The cultivar choice is based on several factors. One is availability of bulbs from Holland. This usually means at least an acre of production. Then, cultivars are selected based on the best thinking as to whether a given variety would be a good one for North American forcing and markets. We try to grow a cultivar for at least three years, although this is not always possible.

In addition to our own trials, we have adapted information from The Holland Bulb Forcer's Guide (de Hertogh) for some cultivars. Nearly 150 other cultivars are presented with information based on Dutch research, with suggestions on how to adapt this information to local conditions.